题解

#include<iostream>
using namespace std;
int main(){
int a,b=65;
char c;
cin>>a;
for(int i=1;i<=a;i++){
for(int u=1;u<=i;u++){
if(b>90){
b=65;
}
c=b;
b++;
cout<<c;
}
cout<<endl;
}
return 0;
}